Display device having ultraviolet light blocking properties

ABSTRACT

A display device includes a substrate, a thin film transistor disposed on the substrate, and a display element electrically connected to the thin film transistor. The substrate includes a first substrate layer, a second substrate layer disposed on the first substrate layer, a first barrier layer disposed between the first substrate layer and the second substrate layer, and a first ultraviolet light blocking layer disposed between the first substrate layer and the second substrate layer.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a Division of co-pending U.S. patent applicationSer. No. 16/268,147, filed on Feb. 5, 2019, which claims priority under35 USC § 119 to Korean Patent Application No. 10-2018-0027537, filed onMar. 8, 2018 in the Korean Intellectual Property Office (KIPO), theentire disclosures of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a display device and, morespecifically, to a display device having ultraviolet light blockingproperties.

DISCUSSION OF THE RELATED ART

A display device is a device that generates an image that can be viewedby a user. Display devices have been incorporated into a wide variety ofelectronic products such as information devices, for example,smartphones and the like. Among the various types of display devicescommonly in use, an organic light emitting diode (OLED) display deviceis attracting attention as a display device having excellentcharacteristics, such as a slim profile, light weight, and low powerconsumption.

As outdoor use of information devices such as smartphones increases,display devices may be exposed to sunlight for longer periods of time.Furthermore, ultraviolet light may be used in various processes that arepart of manufacturing display devices. Exposure to ultraviolet light maydamage various components of the display device.

SUMMARY

A display device includes a substrate, a thin film transistor disposedon the substrate, and a display element electrically connected to thethin film transistor. The substrate includes a first substrate layer, asecond substrate layer disposed on the first substrate layer, a firstbarrier layer disposed between the first substrate layer and the secondsubstrate layer, and a first ultraviolet light blocking layer disposedbetween the first substrate layer and the second substrate layer.

A display device includes a substrate, a thin film transistor disposedon the substrate, a display element electrically connected to the thinfilm transistor, and a sensor disposed under the substrate. Thesubstrate includes a first substrate layer, a second substrate layerdisposed on the first substrate layer, and an ultraviolet light blockinglayer disposed between the first substrate layer and the secondsubstrate layer.

A display device includes a substrate having a plurality of ultravioletlight blocking particles disposed therein. A thin film transistor isdisposed on the substrate. A display element is electrically connectedto the thin film transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present disclosure and many of theattendant aspects thereof will be readily obtained as the same becomesbetter understood by reference to the following detailed descriptionwhen considered in connection with the accompanying drawings, wherein:

FIGS. 1, 2, 3, 4, and 5 are cross-sectional views illustrating a displaydevice according to exemplary embodiments of the present disclosure; and

FIGS. 6, 7, 8, 9, and 10 are cross-sectional views illustrating adisplay device according to exemplary embodiments of the presentdisclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In describing exemplary embodiments of the present disclosureillustrated in the drawings, specific terminology is employed for sakeof clarity. However, the present disclosure is not intended to belimited to the specific terminology so selected, and it is to beunderstood that each specific element includes all technical equivalentswhich operate in a similar manner.

Hereinafter, a display device according to exemplary embodiments of thepresent disclosure will be described with reference to FIGS. 1, 2, 3, 4,and 5.

FIGS. 1, 2, 3, 4, and 5 are cross-sectional views illustrating a displaydevice according to exemplary embodiments of the present disclosure.

Referring to FIGS. 1, 2, 3, and 4, a display device 100, according toexemplary embodiments of the present disclosure, may include a substrateSUB, a pixel circuit disposed on the substrate SUB, and a displayelement DE disposed on the pixel circuit. The pixel circuit may includea thin film transistor TFT and a capacitor CAP. The display device 100may further include a protective film 140 disposed under the substrateSUB.

The substrate SUB may include a first substrate layer 111, a firstbarrier layer 112, a second substrate layer 113, a second barrier layer114, and a first ultraviolet light blocking layer 115.

The first substrate layer 111 may include a flexible material that isalso electrically insulating. For example, the first substrate layer 111may include an organic material such as polyimide (PI), polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polyarylate (PAR),polycarbonate (PC), polyetherimide (PEI), polyethersulfone (PS), or thelike. However, the material of the first substrate layer 111 is notlimited thereto, and any material that is relatively flexible andelectrically insulating may be used as the material of the firstsubstrate layer 111.

The first barrier layer 112 may be disposed on the first substrate layer111. The first barrier layer 112 may include an inorganic material. Forexample, the first barrier layer 112 may include a silicon-basedmaterial such as amorphous silicon (a-Si), silicon oxide (SiO_(x)),silicon nitride (SiN_(x)), or the like. The first barrier layer 112 maybe formed on the first substrate layer 111 that is vulnerable to oxygenand moisture. Accordingly, the first barrier layer 112 is configured toprotect the first substrate layer 111 from damage and is configured toprevent impurities such as oxygen and moisture from permeating into thesensitive layers of the display device 100.

The second substrate layer 113 may be disposed on the first barrierlayer 112. The second substrate layer 113 may include a flexiblematerial that is electrically insulating. The second substrate layer 113may include a material substantially the same as that of the firstsubstrate layer 111, or may have a thickness substantially the same asthat of the first substrate layer 111. However, the present invention isnot limited thereto, and the first substrate layer 111 and the secondsubstrate layer 113 may include different materials, or may havedifferent thicknesses from each other.

The second barrier layer 114 may be disposed on the second substratelayer 113. The second barrier layer 114 may include an inorganicmaterial. The second barrier layer 114 may include a materialsubstantially the same as that of the first barrier layer 112, or mayhave a thickness substantially the same as that of the first barrierlayer 112. However, the present invention is not limited thereto, andthe first barrier layer 112 and the second barrier layer 114 may includedifferent materials, or may have different thicknesses from each other.The second barrier layer 114 may be formed on the second substrate layer113 that is vulnerable to oxygen and moisture thereby protecting thesecond substrate layer 113 from damage and preventing impurities such asoxygen and moisture from permeating into the display device 100.

The first ultraviolet light blocking layer 115 may be disposed betweenthe first substrate layer 111 and the second substrate layer 113.

The display device 100 may be exposed to ultraviolet light that is castupon a bottom of the substrate SUB. Here, the ultraviolet light may befrom sunlight, or may be ultraviolet light used during a process ofmanufacturing the display device 100. For example, ultraviolet light maybe used during the process of manufacturing the display device 10 tocure members formed under the substrate SUB.

The ultraviolet light cast onto the bottom of the substrate SUB mayadversely affect the thin film transistor TFT, the capacitor CAP, and/orthe display element DE. The first ultraviolet light blocking layer 115may be formed in the substrate SUB thereby blocking the ultravioletlight from traveling to the bottom of the substrate SUB. Accordingly,damage of the thin film transistor TFT, the capacitor CAP, and thedisplay element DE disposed over the substrate SUB may be prevented.

The first ultraviolet light blocking layer 115 may include a materialabsorbing ultraviolet light.

In an exemplary embodiment of the present disclosure, the firstultraviolet light blocking layer 115 may include an organic materialsuch as a benzophenone compound, a benzotriazole compound, a benzoatecompound, a cyanoacrylate compound, a triazine compound, an oxanilidecompound, and/or a salicylate compound.

Examples of the benzophenone compound may include, for example,2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,2-2-dihydroxybenzophenone, 2,2′,4′,4′-tetrahydroxybenzophenone,2-hydroxy-4-octylbenzophenone.4-dodecyloxy-2′-hydroxy-4,4′-dimethoxybenzophenone, and the like.

Examples of the benzotriazole compound may include2-(5-methyl-2-hydroxyphenyl)benzotriazole,2-(2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole,2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole,2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole,2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole,2-(3,5-di-t-acyl-2-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-5′-t-octylphenyl)benzotriazole, and the like.

Examples of the benzoate compound may include2,4-di-t-butylphenyl-3′,5′-di-t-butyl-4-hydroxybenzoate and the like.

Examples of the triazine compound may include2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,and the like.

Examples of the salicylate compound may include phenyl salicylate,4-t-butylphenylsalicylate, etc.

Chemical formulas of the benzophenone compound and the benzotriazolecompound from among the above-stated ultraviolet light absorbent organicmaterials are shown below.

In Formula 1 above, R₁ may be hydrogen (H), an alkyl group, or ahydroxyl group, R₂ may be hydrogen (H), an alkyl group, or a phenylgroup, R₃ may be hydrogen (H) or an alkyl group, and R₄ may be hydrogen(H) or an alkoxy group.

In Formula 2 above, R₅ may be hydrogen (H) or an alkyl group.

In Formulas 1 and 2, each of the benzophenone compound and thebenzotriazole compound has a hydroxyl group (—OH). The first ultravioletlight blocking layer 115 may include, for example, a monomer materialhaving a hydroxyl group (—OH), which may provide hydrogen bonding.Ultraviolet light from outside may be absorbed, for example, due to anexcited-state intramolecular proton transfer (ESIPT) phenomenon. Forexample, the first ultraviolet light blocking layer 115 may include acompound having atoms adjacent to a hydroxyl group (—OH) and havingnon-covalent electron pairs, such as oxygen (O) atoms or nitrogen (N)atoms, where hydrogen bonding may be generated between a hydroxyl group(—OH) and the atoms having non-covalent electron pairs. The compound inthe ultraviolet light blocking layer 115 excited by absorbingultraviolet light may undergo phototautomerization, in which protonsmove in excited molecules, and thus hydrogen (H) atoms may be releasedfrom the hydroxyl group (—OH) to form a stable keto-form molecules. As aresult, heat may be released. Therefore, ultraviolet light incident ontothe first ultraviolet light blocking layer 115 may be converted intoheat energy and radiated to the outside, which may reduce or preventultraviolet light from being transmitted into the display device 100.

According to an exemplary embodiment of the present disclosure, thefirst ultraviolet light blocking layer 115 may include an inorganicmaterial such as calcium oxide (CaO) and/or lithium fluorine (LiF). Forexample, when supplying oxygen on calcium after depositing the calcium,a layer on which the calcium is deposited may react with the oxygen toturn into calcium oxide (CaO), and the first ultraviolet light blockinglayer 115 including calcium oxide (CaO) may be formed. Alternatively,the first ultraviolet light blocking layer 115 may be formed by exposingdeposited calcium to ultraviolet light in an oxygen atmosphere.

In an exemplary embodiment of the present disclosure, the firstultraviolet light blocking layer 115 may be disposed between the firstsubstrate layer 111 and the first barrier layer 112 as illustrated inFIG. 1, or may be disposed between the first barrier layer 112 and thesecond substrate layer 113 as illustrated in FIG. 2. The substrate SUBmay include single ultraviolet light blocking layer disposed between thefirst substrate layer 111 and the second substrate layer 113.

In an exemplary embodiment of the present disclosure, the substrate SUBmay further include a second ultraviolet light blocking layer 116 asillustrated in FIG. 3. The second ultraviolet light blocking layer 116may be disposed between the first substrate layer 111 and the secondsubstrate layer 113. The second ultraviolet light blocking layer 116 maybe formed in the substrate SUB thereby blocking the ultraviolet lightthat is cast onto the bottom of the substrate SUB. Accordingly, damageof the thin film transistor TFT, the capacitor CAP, and the displayelement DE disposed over the substrate SUB may be prevented.

The second ultraviolet blocking layer 116 may include a materialsubstantially the same as that of the first ultraviolet blocking layer115, or may have a thickness substantially the same as that of the firstultraviolet blocking layer 115. However, the present invention is notlimited thereto, and the first ultraviolet blocking layer 115 and thesecond ultraviolet blocking layer 116 may include different materials,or may have different thicknesses from each other.

The first ultraviolet blocking layer 115 may be disposed between thefirst substrate layer 111 and the first barrier layer 112, and thesecond ultraviolet blocking layer 116 may be disposed between the firstbarrier layer 112 and the second substrate layer 113. The substrate SUBmay include double ultraviolet light blocking layers disposed betweenthe first substrate layer 111 and the second substrate layer 113.

In an exemplary embodiment of the present disclosure, the firstultraviolet light blocking layer 115 may be disposed between the firstsubstrate layer 111 and the second substrate layer 113 instead of thefirst barrier layer 112 as illustrated in FIG. 4. For example, thesubstrate SUB might not include the first barrier layer 112, and mayinstead include the first ultraviolet light blocking layer 115. Thefirst ultraviolet light blocking layer 115 may act as the first barrierlayer 112.

The first ultraviolet light blocking layer 115 may include an inorganicmaterial such as calcium oxide (CaO) and/or lithium fluorine (LiF) amongthe aforementioned organic material and inorganic material. Accordingly,the first ultraviolet light blocking layer 115 may block ultravioletlight, and may prevent impurities such as oxygen and moisture frompermeating into the display device 100.

A buffer layer 121 may be disposed on the substrate SUB. The bufferlayer 121 may prevent impurities from permeating through the substrateSUB. Further, the buffer layer 121 may planarize the surface of thesubstrate SUB. Alternatively, the buffer layer 121 may be omitted.

The thin film transistor TFT and the capacitor CAP may be disposed onthe buffer layer 121. The thin film transistor TFT may supply voltage orcurrent to the display element DE. The display device 100 may include athin film transistor with a top-gate structure, however, the presentinvention is not limited thereto. The display device 100 may include athin film transistor with a bottom-gate structure. The thin filmtransistor TFT may include a first active pattern 122 a, a gateelectrode 124 a, a source electrode 128 a, and a drain electrode 128 b.The capacitor CAP may maintain a voltage of the thin film transistorTFT. The capacitor CAP may include a lower electrode 124 b and an upperelectrode 126.

A semiconductor layer 122 a and 122 b may be disposed on the bufferlayer 121. The semiconductor layer 122 a and 122 b may include the firstactive pattern 122 a and a second active pattern 122 b. The first activepattern 122 a and the second active pattern 122 b may be spaced apartfrom each other. The semiconductor layer 122 a and 122 b may includeamorphous silicon, polycrystalline silicon, or the like. Alternatively,the semiconductor layer 122 a and 122 b may include an oxidesemiconductor.

A first insulation layer 123 may be disposed on the semiconductor layer122 a and 122 b. The first insulation layer 123 may insulate the gateelectrode 124 a from the first active pattern 122 a, and may insulatethe lower electrode 124 b from the second active pattern 122 b. Thefirst insulation layer 123 may include silicon nitride (SiN_(x)),silicon oxide (SiO_(x)), or the like.

A first conductive layer may be disposed on the first insulation layer123. The first conductive layer may include the gate electrode 124 a andthe lower electrode 124 b. The gate electrode 124 a may at leastpartially overlap the first active pattern 122 a. The lower electrode124 b may be spaced apart from the gate electrode 124 a, and may atleast partially overlap the second active pattern 122 b. A thin filmtransistor including the second active pattern 122 b and the lowerelectrode 124 b acting as a gate may be defined. The first conductivelayer may include gold (Au), silver (Ag), copper (Cu), nickel (Ni),platinum (Pt), palladium (Pd), aluminum (Al), molybdenum (Mo), and/ortitanium (Ti).

A second insulation layer 125 may be disposed on the first conductivelayer. The second insulation layer 125 may insulate the upper electrode126 from the lower electrode 124 b. The second insulation layer 125 mayinclude silicon nitride (SiN_(x)), silicon oxide (SiO_(x)), or the like.

A second conductive layer may be disposed on the second insulation layer125. The second conductive layer may include the upper electrode 126.The upper electrode 126 may at least partially overlap the lowerelectrode 124 b. The second conductive layer may include Au, Ag, Cu, Ni,Pt, Pd, Al, Mo, and/or Ti.

A third insulation layer 127 may be disposed on the second conductivelayer. The second insulation layer 125 and the third insulation layer127 may together insulate both the source electrode 128 a and the drainelectrode 128 b from the gate electrode 124 a. The third insulationlayer 127 may include silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), or the like.

A third conductive layer may be disposed on the third insulation layer127. The third conductive layer may include the source electrode 128 aand the drain electrode 128 b. The source electrode 128 a and the drainelectrode 128 b may be in contact with the first active pattern 122 a.For example, the source electrode 128 a and the drain electrode 128 bmay be in contact with the first active pattern 122 a through respectivecontact holes formed in the first insulation layer 123, the secondinsulation layer 125, and the third insulation layer 127. The thirdconductive layer may include Au, Ag, Cu, Ni, Pt, Pd, Al, Mo, and/or Ti.For example, the third conductive layer may be formed as a multi-layeredstructure such as Mo/Al/Mo or Ti/Al/Ti.

A planarization layer 129 may be disposed on the third conductive layer.The planarization layer 129 may provide a planarized surface over thethird conductive layer. The planarization layer 129 may include anorganic material such as photoresist, polyacrylate-based resin,polyimide-based resin, siloxane-based resin, acryl-based resin,epoxy-based resin, or the like.

The display element DE may be disposed on the planarization layer 129.The display element DE may be configured to emit light based on voltageor current supplied from the thin film transistor TFT. In an exemplaryembodiment of the present disclosure, the display element DE may be anorganic light emitting element, and may include a first electrode 131,an organic light emitting layer 133, and a second electrode 134.However, the display element DE is not limited thereto, and variousdisplay elements such as a liquid crystal display element, or the likemay be used as the display element DE.

The first electrode 131 may be disposed on the planarization layer 129.The first electrode 131 may be patterned for each pixel of the displaydevice 100. The first electrode 131 may be in contact with the drainelectrode 128 b. For example, the first electrode 131 may be in contactwith the drain electrode 128 b through a contact hole formed in theplanarization layer 129. The first electrode 131 may be a reflectiveelectrode. The first electrode 131 may include a reflective layer formedof silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium(Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Jr), chromium(Cr), or the like and a transmitting layer formed of indium tin oxide(ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In₂O₃),or the like. For example, the first electrode 131 may be formed as amulti-layer structure such as ITO/Ag/ITO.

A pixel defining layer 132 may be disposed on the planarization layer129 around the first electrode 131. The pixel defining layer 132 maycover an edge of the first electrode 131, and may include an openingthat exposes a center of the first electrode 131. The pixel defininglayer 132 may include an organic material such as photoresist,polyacrylate-based resin, polyimide-based resin, siloxane-based resin,acryl-based resin, epoxy-based resin, or the like.

The organic light emitting layer 133 may be disposed on the firstelectrode 131. The organic light emitting layer 133 may be disposed inthe opening of the pixel defining layer 132.

The organic light emitting layer 133 may be formed of a low molecularorganic material or a high molecular organic material. When the organiclight emitting layer 133 is formed of the low molecular organicmaterial, a hole injection layer (HIL) and a hole transport layer (HTL)may be formed between the first electrode 131 and the organic lightemitting layer 133, and an electron transport layer (ETL) and anelectron injection layer (EIL) may be formed on the organic lightemitting layer 133. When the organic light emitting layer 133 is formedof the high molecular organic material, the HTL may be formed betweenthe first electrode 131 and the organic light emitting layer 133.

The second electrode 134 may be disposed on the organic light emittinglayer 133. The second electrode 134 may be commonly provided to thepixels. The second electrode 134 may be a transmitting electrode. Forexample, the second electrode 134 may be formed of metal, metal alloy,metallic nitride, transparent metallic oxide, transparent conductivematerial, or the like.

A thin film encapsulation layer encapsulating the display element DE maybe formed on the second electrode 134. The thin film encapsulation layermay include at least one organic layer and at least one inorganic layer.

The organic layer may include a polymer, and may be a single layer or astacked layer including, for example, one of polyethylene terephthalate,polyimide, polycarbonate, epoxy, polyethylene, and polyacrylate. In anembodiment, the organic layers may include polyacrylate. Specifically,the organic layer may include a polymerized monomer compositionincluding diacrylate-based monomer and triacrylate-based monomer. Themonomer composition may further include monoacrylate-based monomer.Also, the monomer composition may further include a well-knownphotoinitiator such as trimethyl benzoyl diphenyl phosphine oxide(“TPO”), however, the present invention is not limited thereto.

The inorganic layer may be a single layer or a stacked layer includingmetal oxide or metal nitride. In an embodiment, the inorganic layers mayinclude one of SiN_(x), Al₂O₃, SiO₂, and TiO₂.

The protective film 140 may be disposed under the substrate SUB. Theprotective film 140 may absorb impact from outside thereby preventingthe display device 100 from being damaged by the impact. The protectivefilm 140 may be formed of a material containing air such as cushion,sponge, or the like to absorb impact. For example, the protective film140 may include polyethylene terephthalate (PET) or the like. Anadhesive layer may be formed between the substrate SUB and theprotective film 140 and may attach the protective film 140 to thesubstrate SUB.

Referring to FIG. 5, the display device 100, according to an embodimentof the present disclosure, may further include a sensor 151 disposedunder the substrate SUB. For example, the sensor 151 may be disposedunder the substrate SUB with the protective film 140 disposed inbetween.

In an exemplary embodiment of the present disclosure, the sensor 151 maybe a fingerprint recognition sensor configured to sense a fingerprint ofa user. The sensor 151 may be disposed in a display region on which thedisplay element DE is located.

The sensor 151 may be attached to a bottom of the protective film 140via an adhesive layer 152. Ultraviolet light may be cast to a bottom ofthe substrate SUB to harden the adhesive layer 152. If the ultravioletlight passes through the substrate SUB, the thin film transistor TFT,the capacitor CAP, or display element DE may be adversely affected.Further, when the ultraviolet light is cast onto the substrate SUB, astain may be generated on the display device 100 due to the ultravioletlight.

To solve the aforementioned problem, the substrate SUB may include anultraviolet light blocking layer 115 that at least partially overlapsthe sensor 151 in a plan view. In an exemplary embodiment of the presentdisclosure, the ultraviolet light blocking layer 115 may be patternedsuch that at least a portion of the ultraviolet light blocking layer 115overlaps the sensor 151. A width of the ultraviolet light blocking layer115 may be greater than or substantially the same as a width of thesensor 151.

A cushion layer 153, an embossing layer 154, and a light shielding layer155 may be disposed on a portion of the bottom of the protective layer140 on which the sensor 151 is not disposed.

The cushion layer 153 may be disposed under the substrate SUB, and mayreduce impact that may otherwise be applied to the display device 100.The cushion layer 153 may include polymer such as polypropylene (PP) orpolyethylene (PE). In an exemplary embodiment of the present disclosure,the cushion layer 153 may include any material that has a density ofabout 0.5 g/cm³ or more. The cushion layer 153 may be formed as a foamor gel. In an exemplary embodiment of the present disclosure, thecushion layer 153 may include a material having high elastic force, forexample, rubber.

The embossing layer 154 may be disposed between the substrate SUB andthe cushion layer 153. The embossing layer 154 may be adhesive. Theembossing layer 154 may include polyethylene terephthalate (PET) or thelike.

The shielding layer 155 may be configured to prevent elements disposedunder the substrate SUB from being viewed. The shielding layer 155 maybe disposed between the substrate SUB and the embossing layer 154. Theshielding layer 155 may be formed of polyethylene terephthalate (PET) orthe like by a screen printing process or the like. Hereinafter, adisplay device according to some exemplary embodiments of the presentdisclosure will be described with reference to FIGS. 6, 7, 8, 9, and 10.

FIGS. 6, 7, 8, 9, and 10 are cross-sectional views illustrating adisplay device according to some exemplary embodiments of the presentdisclosure.

Referring to FIGS. 6, 7, 8, 9, and 10, a display device 200, accordingto some exemplary embodiments of the present disclosure may include asubstrate SUB, a pixel circuit disposed on the substrate SUB, and adisplay element DE disposed on the pixel circuit. The pixel circuit mayinclude a thin film transistor TFT and a capacitor CAP. The displaydevice 200 may further include a protective film 240 disposed under thesubstrate SUB.

In describing various elements of the display device 200 with referenceto FIGS. 6, 7, 8, 9, and 10, some elements may be substantially the sameas or similar to corresponding elements of the display device 100described with reference to FIGS. 1, 2, 3, 4, and 5. To the extent thata detailed description of elements is omitted, it may be assumed thatthese elements are at least similar to the corresponding elements thathave already been described.

Referring to FIGS. 6, 7, and 8, the substrate SUB may include a firstsubstrate layer 211, a first barrier layer 212, a second substrate layer213, and a second barrier layer 214.

The first substrate layer 211 and/or the second substrate layer 213 mayinclude a matrix including an organic material and a plurality ofultraviolet light blocking particles dispersed within the matrix.

The ultraviolet light blocking particles may include an organic materialsuch as a benzophenone compound, a benzotriazole compound, a benzoatecompound, a cyanoacrylate compound, a triazine compound, an oxanilidecompound, and/or a salicylate compound.

An amount of the ultraviolet light blocking particles in the matrix mayvary, for example, depending on the thickness of the first and/or secondsubstrate layers 211 and/or 213, the absorption wavelength range of theultraviolet light blocking particles, or the like. For example, theultraviolet light blocking particles may be included in an amount ofabout 0.1 wt % to about 20 wt %.

The matrix may include an organic material based on which the filmcharacteristics of the first and/or second substrate layers 211 and/or213, and may include, for example, an organic material such as polyimide(PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET),polyarylate (PAR), polycarbonate (PC), polyetherimide (PEI),polyethersulfone (PS), or the like.

Various methods may be used to form the first and/or second substratelayers 211 and/or 213. For example, an organic film forming layer,including, for example, a mixture of a first monomer including anorganic material for forming the matrix and a second monomer includingthe ultraviolet light blocking particles, may be accommodated on acarrier substrate by using methods, such as evaporation, inkjetprinting, screen printing, and spin coating.

In an exemplary embodiment of the present disclosure, the ultravioletlight blocking particles may be cross-linked within the matrix.

The ultraviolet light blocking particles may include, for example, anacrylate group, a methacrylate group, and/or an epoxy group, and mayhave a structure in which the material or compound is coupled with atleast one functional group from among an acrylate group, a methacrylategroup, and an epoxy group. The functional group may be cross-linkedwithin the matrix, which may provide a more dense film characteristic tothe first and/or second substrate layers 211 and/or 213.

Referring to FIG. 6, in an exemplary embodiment of the presentdisclosure, the first substrate layer 211 may include a first matrix 211b including an organic material and a plurality of first ultravioletlight blocking particles 211 a dispersed in the first matrix 211 b, andthe second substrate layer 213 might not include the ultraviolet lightblocking particles. The first substrate layer 211 may block ultravioletlight cast to a bottom of the display device 200.

Referring to FIG. 7, in another embodiment, the second substrate layer213 may include a second matrix 213 b including an organic material anda plurality of second ultraviolet light blocking particles 213 adispersed in the second matrix 213 b, and the first substrate layer 211might not include the ultraviolet light blocking particles. The secondsubstrate layer 213 may block ultraviolet light cast to the bottom ofthe display device 200.

Referring to FIG. 8, according to an exemplary embodiment of the presentdisclosure, the first substrate layer 211 may include a first matrix 211b including an organic material and a plurality of first ultravioletlight blocking particles 211 a dispersed in the first matrix 211 b, andthe second substrate layer 213 may include a second matrix 213 bincluding an organic material and a plurality of second ultravioletlight blocking particles 213 a dispersed in the second matrix 213 b. Thefirst and second substrate layers 211 and 213 may block ultravioletlight cast to the bottom of the display device 200.

Referring to FIG. 9, the display device 200, according to an exemplaryembodiment of the present disclosure, may further include a sensor 251disposed under the substrate SUB. For example, the sensor 251 may bedisposed under the substrate SUB with the protective film 240 disposedin between. The first substrate layer 211 may include the firstultraviolet light blocking particles 211 a overlapping the sensor 251 ina plan view. The first ultraviolet light blocking particles 211 a may bedispersed within the first matrix 211 b to overlap the sensor 251, andthe first ultraviolet light blocking particles 211 a might not belocated in a portion of the first substrate layer 211 which does notoverlap the sensor 251. For example, a width of a region in which thefirst ultraviolet light blocking particles 211 a are located may begreater than or substantially the same as a width of the sensor 251.

Referring to FIG. 10, the substrate SUB of the display device 200,according to an exemplary embodiment of the present disclosure, mightnot include the first substrate layer 211, the first barrier layer 212,the second substrate layer 213, and the second barrier layer 214,different from the substrate SUB of the display device 200 describedabove. The substrate SUB may include a plurality of ultraviolet lightblocking particles SUBa dispersed therein.

In an exemplary embodiment of the present disclosure, the substrate SUBmay include an organic material such as polyimide (PI), polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polyarylate (PAR),polycarbonate (PC), polyetherimide (PEI), polyethersulfone (PS), or thelike. In an exemplary embodiment of the present disclosure, thesubstrate SUB may include glass, quartz, ceramic, metal, or the like.

The display device, according to exemplary embodiments of the presentdisclosure, may be applied to a display device included in a computer, anotebook, a mobile phone, a smartphone, a smart pad, a PMP, a PDA, anMP3 player, or the like.

Although the display devices, according to exemplary embodiments of thepresent invention, have been described with reference to the drawings,the illustrated embodiments are examples, and may be modified andchanged by a person having ordinary knowledge in the relevant technicalfield without departing from the technical spirit of the presentdisclosure.

What is claimed is:
 1. A display device, comprising: a substrate; a thinfilm transistor disposed on the substrate; a display elementelectrically connected to the thin film transistor; and a sensordisposed under the substrate, wherein the substrate comprises: a firstsubstrate layer; a second substrate layer disposed on the firstsubstrate layer; and an ultraviolet light blocking layer disposedbetween the first substrate layer and the second substrate layer.
 2. Thedisplay device of claim 1, wherein the ultraviolet light blocking layeroverlaps the sensor.
 3. The display device of claim 1, wherein thesensor is a fingerprint recognition sensor.